Platen support for heat processing machines



May 5, 1931. J. A. STEVENS 1,803,779

PLTEN SUPPORT FOR HEAT PROCESSING MACILINES Filed Aug. 14, 192s 5sneetsheet 1 Il I' Il Il II lIl l Il II L L-l II ll H/ll'll Il May 5,`1931. J. A. STEVENS 1 1,803,779

PLATEN SUPPORT FOR HEAT PROCESSING MACHINES Filed Aug. 14, 1928 3Sheets-Sheet 2 INVENTOR May 5, 1931. 1. A. Sfax/Em; l 1,803,779

PLATEN SUPPORT FOR HEAT PROCESSING MACHINES INVENTQR Patented May 5,1931 UNITED STATES moana PATENT OFFlCE JOHN A. STEVENS, OF LOWELL,MASSACHUSETTS, ASSIGNOR TO THE UPSON COMPANY,

OF LOCKPORT, NEW YORK, A CORPORATION OF NEW YORK 'TIO 'PLATEN SUIPORT"FOR HEAT PROCESSING MACHINES Application filed August 14, 1928. SerialNo. 299,562.

My present invention relates to the manufacture of sheets, slabs,boards, and similar products, particularly when composed in whole or inpart of material originally in the plastic state, and which requires anapplication of heat and pressure during its formative stage, and theinvention has for its object to provide a simple economical, elicientand convenient machine for accomplishing this work. The improvements aredirected in part towardthe provision of opposed upper and lower heatingelements with means for adjustably and resiliently supporting them sothat their distance apart regulating the thickness of the product andalso the pressure which it undergoes may be easily and quickly adjusted.

To these and other ends the invention resides in certain improvementsand combinations of parts, all as will be hereinafter more ullydescribed, the novel features being pointed out in the claims at the endof this specification.

In the drawings:

s Fig. 1 is a rather diagrammatic side view or outline view of the sheetforming machine showing the application thereto of heating and pressureelements vconstructed in accordance with and illustrating ne embodimentof my invention;

Fig. 2 is an enlarged fragmentary side view of a portion of the platensection of the machine showing one platen unit complete;

Fig. 3 is a transverse section through the machine showing a side viewof one of the Aplaten units;

Fig. 4 is an enlarged fragmentary detail section on the line 4 4 of Fig.2;

Fig. 5 is a similar view showing the platens adjusted to a differentrelationship;

Fig. 6 is a section on the line 6 6 of Fig. 4, and

Fig. 7 is a perspective view of a washer or shim that is used forpurposes of adjustment.

Similar reference numerals throughout the several views indicate thesame parts.

Although its advantages and functions are not necessarily limited tosuch use, the present machine representing one embodiment or applicationof the invention, has been specially designed for the manufacture of aspecial wallboard, preferably composed of two outer paper facings, orliners, as they are called, and a cellular lire-resisting and insulatingmineral body of substantial thickness therebetween. It has beendiscovered that a mixture having as the principal ingredient sodiumsilicate and a. filler of finely comminuted or powdered dolomiticlimestone provides a suitable body between the paper walls for thepurposes of producing such a product. Such a mixture is intiunescent incharacter, and puffs upinto a cellular or sponge-like consistency whenconiined and subjected to a proper degree of heat. lt can later behardened and dried and assumes a solid texture, in which state it ishardand relatively stid without being brittle.'V My invention contemplatesproducing such a '70 board continuously in a moving strip or sheet thatisy linally cut into lengths.

To lirst describe in general the mode of manufacturing such a board inaccordance with my invention, and assuming that a board with two facingsor liners is to be made (though one liner alone may be used or none atall resulting in a solid plastic product) I provide a supply of paperconsisting of two strips which are brought together one upon another anda suitable amount of the plastic material fed between them. Thislaminated mass is passed between a pair of upper and lower heatedplatensl which present smooth walls of considerable extent and whoseseparation regulates the thickness of the product. These platens areheated by steam or otherwise, but if by steam, then a pressure of from125 to 20() pounds may be used, the speed of passage of the materialbetween them being' a factor in determining the pressure used. From theplatens the sheet passes in a formative and relatively soft stateimmediately into a closely adjacent hardening oven where it is treatedby direct contact with a heated gas. l prefer to use hot air. ln thisoven the sheet hardens and it becomes set suiiiciently so that it can bemanipulated without danger of injury or distortion. l am, therefore,able

to place and do place just beyond this hard- 100 ening oven a feedingdevice preferably in the form of a pair of driven feed rolls, which drawthe material all the way from its source at the feed end of the machinethrough the platens, past a slitting and trimming device located betweenthe platens and the hardening oven, and through the hardening oven. Justbeyond the feed rollers the sheet may be severed by a suitable cuttingdevice into the desired lengths. `With its manipulationfrom this pointon this invention is not concerned, and hence only such portion of themachine is shown.

Referring more particularly to theV drawings, and to Fig. 1. thereof, 1indicates a suitable bed or base frame having at the feed end thereofpaper rolls 2'and 3 for the supply of liners. The plastic material isfed from a conventionally shown hoppert between rolls 5 and 6 beneathit. The paper from Vroll 2 passes over the top of roll 6 and thencearound and under it in a reverse direction. The paper from roll 3 passesover roll 5 and thence under roll 6 continuing in the same direction, sothat the plastic material is deposited in suitable quantities betweenthe two liners X and Y, and is held between them as the threeply masspasses into the platen section.

The platens of this section arc'inade of a plurality of upper units 7and lower units 8 spaced apart for the desired thickness. the sheetenierges as shown at XY from the end of this section, its edgesareftrinnnedby suitable trimming devices 9, and it may be slit byanother' cutter indicated conventionally at 10 in Fig. 1 into twostrips, if desired. It then immediately passes into an oven-11', wherethe hardening takes place. Just beyond this oven are the feed rollers 12suitably driven, which pull the sheet through all of the travel abovedescribed to this point.

As before indicated, my invention is particularly concerned with theconstruction, arrangement, and manipulation of the platen elements 7 and8 relatively to each other to regulate boththe thickness of the sheet orboard and the amount of pressure applied thereto. Referring moreparticularly to Figs. 2 and 3, the lower platens 8 are laid side by sideto present a` substantially continuous table or under surface. Theyextend transversely of the ma chine and are supported at their ends byprojecting perforated lugs 13 resting on sleeves lil surroundingupstanding guide rods 14" which pass through the lugs and which guiderods are suitably adjustably bolted to the main frame 1 by suitable lagand locl nuts 15. rIlhese under platens may be leveled and aligned bymeans of shims or washers placed beneath the sleeves 11i.

The upper platens 7 are preferably slightly separated from each other asshown, and are arranged to be raised and lowered in parallelism withreference to the table constituted by the lower platens 8. For thispurpose they are made in sections, as best shown in Fig. 2. As indicatedin that figure there are in the present instance four platens to a unit,and they are connected together by a pair of relatively transverseI-beams 22 bolted thereto at 23. Connecting these I-beams at anintermediate balancing point is a cross beam 24 provided with a centrallifting eye 25 for the attachment of raising and lowering connections,which form no part of the present invention and which constitute theSubj ect matter of a separate application being filed concurrentlyherewith.

These upper platens 7 are similar to the lower plat-ens 8 except thatthey are, of course, finished olf on the lower side instead of the upperside. They are provided with perforated lugs26 at their ends which alsoengage over and are adapted to slide vertically upon the guide rods 14a.Above the lugs 13 of the lower platen are provided sleeves 27 on thelrods upon which rest compression coil springs 28 surrounding therodsand which in turn support the lugs 26 of the upper platens 7. Thesesprings are 'of such tension as to support the weight of the upperplatens and the upper platen section at a minimum degree of separationfrom the lower vplatens 8, and again shims may be used to regulate thisseparation by interposing them either between the sleeves 27 and thelower platen lugsl or between the ends ofthe springs and their abuttingsurfaces. I prefer the latter position.l

These shims are preferably of the shape shown 'in Fig. 7 enabling one ormore of them to be slipped under the spring 28 in the manner indicatedat 19 in Fig. 4. Compare the separation of the upper and'lower platensin this ligure with that in Figure 5, where no' shims are present. v

VBoth upper and lower platens are heated by steam through inlet andexhaust connections 20 and 21, the supplyV pipes to which are notv shownbecause they are not material f to a disclosure of the presentinvention.

' Cheek plates are provided alongv the ends of the lower platen toconline the edges of the traveling sheet that is being formed both as aguiding medium and to prevent, in a measure at least, plastic materialfrom exud- -ing before it is hardened suiiciently tohold its own form.In the` presentV instance these consist of wooden or metallic strips18'suitably secured to the lower platen table.

With the platens constructed and arranged in accordance with myinvention as above described in a machine of this character, and

particularly one operating on the character of u materials that I haveset forth as an instance of its use or applica-tion, the compressionexerted by the weight of the upper platen on the board or sheet that isbeing formed, and

the thickness of the latter can be nicely and conveniently regulated.Jams are prevented or can be readily relieved at a given point, and thefloating nature of the resiliently supported upper platens promotes theeasy riding ot the sheet as it is pulled through the machine by the pullor feed rolls.

In Figure 5 I have shown a slight modilication in the manner of mountingthe lower platen 8 so that it may also be resiliently supported. To thisend a spring 29 similar to the spring 28 is substituted for the sleeve14 which renders the lower platen table less rigid, and gives it aslight elasticity in its movement or engagement with the sheet thatrenders it less harsh to the passage of the latter through the machine.

I claim as my invention:

1. In a heat processing machine for sheets and boards, the combinationwith a lower platen element, an upper platen element, and meansindependent of said platen elements for drawing sheet materialcontinuously between said elements, of a resilient support for one ofsaid platen elements to maintain it properly spaced 'from the otherelement.

' 2. In a heat processing machine 'for sheets and boards, thecombination with a lower platen element, an upper platen element, andmeans independent of said platen elements for drawing. sheet materialcontinuously between said elements, of a resilient support for the upperplaten element to maintain it properly spaced from the lower element.

3. In a heat processing machine for sheets and boards, the combinationwith a lower platen element, an upper platen element, and

means independent of said platen elements for drawing sheet materialcontinuously between said elements, of a resilient support 'for thelower platen element to maintain it properly spaced from the upperelement.

4. In a heat processing machine tor sheets and boards, the combinationwith a lower platen element, an upper platen element, and meansindependent ot' said platen elements for drawing sheet materialcontinuously between said elements, of a resilient support for eachplaten element yieldingly spacing them the proper distance from eachother.

5. In a heat processing machine for sheets and boards, the combinationwith a lower platen element, an upper platen element and means fordrawing sheet material continuously between the same, of a supporthaving guides thereon, lugs on one of the platen elements movablevertically on the guides and springs associated with the latter uponwhich said platen element rests.

6. -In a heat processing machine for sheets and boards, the combinationwith a lower platen element, an upper platen element and means fordrawing sheet material continuously between the same, of a supporthaving guides thereon cooperating with one of the platen elements,springs associated with the guides and upon which said platen elementrests and means for raising and lowering an abutting surface of thespring.

7. In a heat processing machine for sheets and boards, the combinationwith a lower platen element, an upper platen element and means fordrawing sheet material continuously between the same, oi a resilientsupport tor one of said platen elements to maintain it properly spacedfrom theV other element, and means extending along the end of one platenelement to coniine the edges of the sheet and limit the closing togetherof the platen elements.

8. In a heat processing machine for sheets and boards, the combinationof a pair of spaced platens, a support for one of the platens, means formaintaining a minimum distance between the platens while permitting oneto movein a direction away from the other, guide means for the movableplaten serving to hold it against movement transversely of the otherplaten, and means arranged to operate independently of said platens fordrawing the sheets therebetween.

9. In ay heat processing machine for sheets andy boards, the combinationwith a platen element, of a second pla-ten element movable toward andaway from the first mentioned element to vary the spacing between saidelements, stop means to limit the motion of said second element towardsaid first named element, and means independent of said platen elementsfor drawing sheet material through the space between said elements.

10. In a heat processing machine for sheets and boards, the combinationwith a lower platen element, of. an upper platen element movable towardand away from the lower element to vary the spacing between saidelements, stop means to limit the downward motion of said upper elementtoward said lower element to hold said elements a predetermined distanceapart, and means independent of said platen elements for drawing sheetmaterial through the space between said elements.

JOHN A. STEVENS.

